1. Field of the Invention
The present invention relates to a flat display device having an easily replaceable lamp unit.
2. Description of the Related Art
In conventional light transmission-type display panels such as a liquid crystal display panel, a planar light source device called xe2x80x9cbacklightxe2x80x9d for illuminating a display area uniformly is provided on the back side of the light transmission-type display panel. Among such backlights, an edge light type backlight is used widely in which a linear light source is provided along a side face of a light guide plate that is made of a transparent resin.
For example, when a liquid crystal display device has been used for a long time and it has become necessary to replace its linear light source because of deterioration with age, it is difficult to replace only the linear light source because of its fragility. Therefore, it is desirable to replace the entire lamp unit in which the linear light source, a lamp reflector, and rubber holders are integrated with each other. Recently, edge light type backlights having a detachable lamp unit have been proposed.
A liquid crystal display device having a detachable lamp unit will be described below briefly. A light guide plate made of a transparent resin is provided on the back side of a liquid display panel and a lamp unit(s) is provided along one side face of the light guide plate. Or two lamp units are provided on two side faces opposed to each other of the light guide plate, respectively. The lamp unit is composed of at least one linear light source, a lamp reflector for concentrating, toward the light guide plate, light emitted from the linear light source, and rubber holders that hold two respective end portions of each of the linear light source and the lamp reflector. The rubber holders serve to position the linear light source with respect to the lamp reflector and fix the former to the latter as well as to maintain the distance between the linear light sources or between the light source and the lamp reflector. To efficiently introduce, to the liquid crystal display panel, light beams that are output from the light guide plate, a reflection sheet, a diffusion sheet, a lens sheet, etc. are used. These parts are fixed at prescribed positions by a resin or metal frame.
FIG. 6 is a partially sectional view of a lamp unit attachment portion of a liquid crystal display device having a conventional detachable lamp unit. In FIG. 6, the side above a lamp unit 5 is the light guide plate side. In the example shown in FIG. 6, a lamp 6 as a linear light source, a lamp reflector 7, and rubber holders 8 are integrated with each other to form the lamp unit 5. The lamp reflector 7 is fixed, with screws 16, to a resin frame 13 that is a structure member. To replace the lamp unit 5, the lamp unit 5 is removed by disengaging the screws 16.
However, in the structure of FIG. 6 in which the lamp unit 5 is attached to the resin frame 13 with the screws 16, a tool such as a screwdriver is necessary to engage or disengage the screws 16. Therefore, it is difficult to replace the lamp unit 5 quickly. There is another problem that the number of parts is large because of the use of the screws 16 and hence the work of assembling the liquid crystal display device is cumbersome.
The present invention has been made to solve the above problems, and an object of the invention is therefore to improve a flat display device having a detachable lamp unit so that the lamp unit can be replaced quickly and easily.
A flat display device according to the invention comprises a light transmission-type display panel, a light guide plate, a lamp unit and a structure member. The light guide plate has a light output surface opposed to the light transmission-type display panel. The lamp unit includes a linear light source, a light reflector and holders. The linear light source is disposed adjacent to at least one side face of the light guide plate. The lamp reflector concentrates, toward the light guide plate, light emitted from the linear light source. The holders made of a resilient material hold both end portions of the linear light source and the lamp reflector. The lamp unit has a resilient projection toward to the structure member. The structure member supports the lamp unit and a peripheral portion of the light transmission-type display panel and the lamp unit. The structure member has a guide opening for inserting and removing the lamp unit and an engaging hole in which the resilient projection is inserted.
According to the invention, the resilient projection of the lamp unit and the engaging hole of the structure member are engaged and disengaged to each other easily, depend on the resiliency of the resilient projection. Therefore, the lamp unit replacement can be performed more quickly and easily through the guide opening of the structure member than with the conventional attachment structure using screws.
Preferably, in the flat display according to the invention, the resilient projection is formed by bending an end portion of the lamp reflector.
Still preferably, in the flat display device according to the invention, at least one of the holders is formed in close contact with the resilient projection and supports the resilient projection.
Still preferably, in the flat display device according to the invention, at least one of the holders is so molded as to conform to a shape of the resilient projection.
Still preferably, in the flat display device according to the invention, the resilient projection is made of the same material as and molded integrally with at least one of the holders.
Still preferably, in the flat display device according to the invention, a resin mold part provided with the resilient projection is attached to the light reflector.
Still preferably, in the flat display device according to the invention, the light transmission-type display panel is a liquid crystal display panel.